Add pagination

NOTES.md

@@ -1,6 +1,6 @@
 # Notes
 
-## Subscriptions (temp)
+## Subscriptions
 - TODO: remove all logger lines
 
 ## Issues

README.md

@@ -130,7 +130,7 @@ Features in *italics* are in the master branch, but not in the latest release.
     - https://lists.orbitalfox.eu/archives/gemini/2020/001400.html
 - [x] Subscriptions
   - RSS, Atom, and [JSON Feeds](https://jsonfeed.org/) are all supported
-  - So is tracking any page to be notified when it changes
+  - So is tracking a page, to know when its content changes
 - [ ] Stream support
 - [ ] Table of contents for pages
 - [ ] History browser

config/config.go

@@ -237,6 +237,7 @@ func Init() error {
 	viper.SetDefault("subscriptions.popup", true)
 	viper.SetDefault("subscriptions.update_interval", 1800)
 	viper.SetDefault("subscriptions.workers", 3)
+	viper.SetDefault("subscriptions.entries_per_page", 20)
 
 	viper.SetConfigFile(configPath)
 	viper.SetConfigType("toml")

config/default.go

@@ -153,6 +153,9 @@ update_interval = 1800 # 30 mins
 # update times. Any value below 1 will be corrected to 1.
 workers = 3
 
+# The number of subscription updates displayed per page.
+entries_per_page = 20
+
 
 [theme]
 # This section is for changing the COLORS used in Amfora.

default-config.toml

@@ -150,6 +150,9 @@ update_interval = 1800 # 30 mins
 # update times. Any value below 1 will be corrected to 1.
 workers = 3
 
+# The number of subscription updates displayed per page.
+entries_per_page = 20
+
 
 [theme]
 # This section is for changing the COLORS used in Amfora.

display/display.go

@@ -294,7 +294,7 @@ func Init() {
 				}
 				return nil
 			case tcell.KeyCtrlA:
-				Subscriptions(tabs[curTab])
+				Subscriptions(tabs[curTab], "about:subscriptions")
 				tabs[curTab].addToHistory("about:subscriptions")
 				return nil
 			case tcell.KeyCtrlX:
@@ -578,8 +578,8 @@ func Reload() {
 func URL(u string) {
 	t := tabs[curTab]
 	if strings.HasPrefix(u, "about:") {
-		if ok := handleAbout(t, u); ok {
-			t.addToHistory(u)
+		if final, ok := handleAbout(t, u); ok {
+			t.addToHistory(final)
 		}
 		return
 	}

display/handlers.go

@@ -169,34 +169,40 @@ func handleFavicon(t *tab, host, old string) {
 //
 // It does not add the displayed page to history.
 //
-// It returns a bool indicating if the provided URL could be handled.
-func handleAbout(t *tab, u string) bool {
+// It returns the URL displayed, and a bool indicating if the provided
+// URL could be handled. The string returned will always be empty
+// if the bool is false.
+func handleAbout(t *tab, u string) (string, bool) {
 	if !strings.HasPrefix(u, "about:") {
-		return false
+		return "", false
 	}
 
 	switch u {
 	case "about:bookmarks":
 		Bookmarks(t)
-		return true
-	case "about:subscriptions":
-		Subscriptions(t)
-		return true
+		return u, true
 	case "about:newtab":
 		temp := newTabPage // Copy
 		setPage(t, &temp)
 		t.applyBottomBar()
-		return true
+		return u, true
 	}
 
+	if u == "about:subscriptions" || (len(u) > 20 && u[:20] == "about:subscriptions?") {
+		// about:subscriptions?2 views page 2
+		return Subscriptions(t, u), true
+	}
 	if u == "about:manage-subscriptions" || (len(u) > 27 && u[:27] == "about:manage-subscriptions?") {
 		ManageSubscriptions(t, u)
 		// Don't count remove command in history
-		return u == "about:manage-subscriptions"
+		if u == "about:manage-subscriptions" {
+			return u, true
+		}
+		return "", false
 	}
 
 	Error("Error", "Not a valid 'about:' URL.")
-	return false
+	return "", false
 }
 
 // handleURL displays whatever action is needed for the provided URL,
@@ -252,7 +258,7 @@ func handleURL(t *tab, u string, numRedirects int) (string, bool) {
 	App.SetFocus(t.view)
 
 	if strings.HasPrefix(u, "about:") {
-		return ret(u, handleAbout(t, u))
+		return ret(handleAbout(t, u))
 	}
 
 	u = normalizeURL(u)

display/private.go

@@ -20,8 +20,8 @@ import (
 // It will handle setting the bottomBar.
 func followLink(t *tab, prev, next string) {
 	if strings.HasPrefix(next, "about:") {
-		if ok := handleAbout(t, next); ok {
-			t.addToHistory(next)
+		if final, ok := handleAbout(t, next); ok {
+			t.addToHistory(final)
 		}
 		return
 	}

display/subscriptions.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"net/url"
 	"path"
+	"sort"
 	"strconv"
 	"strings"
 	"time"
@@ -20,7 +21,9 @@ import (
 	"github.com/spf13/viper"
 )
 
-var subscriptionPageUpdated time.Time
+// Map page number (zero-indexed) to the time it was made at.
+// This allows for caching the pages until there's an update.
+var subscriptionPageUpdated = make(map[int]time.Time)
 
 // toLocalDay truncates the provided time to a date only,
 // but converts to the local time first.
@@ -30,54 +33,125 @@ func toLocalDay(t time.Time) time.Time {
 }
 
 // Subscriptions displays the subscriptions page on the current tab.
-func Subscriptions(t *tab) {
+func Subscriptions(t *tab, u string) string {
 	logger.Log.Println("display.Subscriptions called")
 
+	pageN := 0 // Pages are zero-indexed internally
+
+	// Correct URL if query string exists
+	// The only valid query string is an int above 1.
+	// Anything "redirects" to the first page, with no query string.
+	// This is done over just serving the first page content for
+	// invalid query strings so that there won't be duplicate caches.
+	correctURL := func(u2 string) string {
+		if len(u2) > 20 && u2[:20] == "about:subscriptions?" {
+			query, err := gemini.QueryUnescape(u2[20:])
+			if err != nil {
+				return "about:subscriptions"
+			}
+			// Valid query string
+			i, err := strconv.Atoi(query)
+			if err != nil {
+				// Not an int
+				return "about:subscriptions"
+			}
+			if i < 2 {
+				return "about:subscriptions"
+			}
+			// Valid int above 1
+			pageN = i - 1 // Pages are zero-indexed internally
+			return u2
+		}
+		return u2
+	}
+	u = correctURL(u)
+
 	// Retrieve cached version if there hasn't been any updates
-	p, ok := cache.GetPage("about:subscriptions")
-	if subscriptionPageUpdated.After(subscriptions.LastUpdated) && ok {
+	p, ok := cache.GetPage(u)
+	if subscriptionPageUpdated[pageN].After(subscriptions.LastUpdated) && ok {
 		logger.Log.Println("using cached subscriptions page")
 		setPage(t, p)
 		t.applyBottomBar()
-		return
+		return u
 	}
 
 	logger.Log.Println("started rendering subscriptions page")
 
-	rawPage := "# Subscriptions\n\n" +
-		"See the help (by pressing ?) for details on how to use this page.\n\n" +
-		"If you just opened Amfora then updates will appear incrementally. Reload the page to see them.\n\n" +
-		"=> about:manage-subscriptions Manage subscriptions\n"
-
-	// curDay represents what day of posts the loop is on.
-	// It only goes backwards in time.
-	// Its initial setting means:
-	// Only display posts older than 26 hours in the future, nothing further in the future.
-	//
-	// 26 hours was chosen because it is the largest timezone difference
-	// currently in the world. Posts may be dated in the future
-	// due to software bugs, where the local user's date is used, but
-	// the UTC timezone is specified. I believe gemfeed does this.
-	curDay := toLocalDay(time.Now()).Add(26 * time.Hour)
-
 	pe := subscriptions.GetPageEntries()
 
-	for _, entry := range pe.Entries { // From new to old
-		// Convert to local time, remove sub-day info
-		pub := toLocalDay(entry.Published)
+	// Figure out where the entries for this page start, if at all.
+	epp := viper.GetInt("subscriptions.entries_per_page")
+	if epp <= 0 {
+		epp = 1
+	}
+	start := pageN * epp // Index of the first page entry to be displayed
+	end := start + epp
+	if end > len(pe.Entries) {
+		end = len(pe.Entries)
+	}
 
-		if pub.Before(curDay) {
-			// This post is on a new day, add a day header
-			curDay = pub
-			rawPage += fmt.Sprintf("\n## %s\n\n", curDay.Format("Jan 02, 2006"))
+	var rawPage string
+	if pageN == 0 {
+		rawPage = "# Subscriptions\n\n" + rawPage
+	} else {
+		rawPage = fmt.Sprintf("# Subscriptions (page %d)\n\n", pageN+1) + rawPage
+	}
+
+	if start > len(pe.Entries)-1 && len(pe.Entries) != 0 {
+		// The page is out of range, doesn't exist
+		rawPage += "This page does not exist.\n\n=> about:subscriptions Subscriptions\n"
+	} else {
+		// Render page
+
+		rawPage += "You can use Ctrl-X to subscribe to a page, or to an Atom/RSS/JSON feed. See the online wiki for more.\n" +
+			"If you just opened Amfora then updates may appear incrementally. Reload the page to see them.\n\n" +
+			"=> about:manage-subscriptions Manage subscriptions\n\n"
+
+		// curDay represents what day of posts the loop is on.
+		// It only goes backwards in time.
+		// Its initial setting means:
+		// Only display posts older than 26 hours in the future, nothing further in the future.
+		//
+		// 26 hours was chosen because it is the largest timezone difference
+		// currently in the world. Posts may be dated in the future
+		// due to software bugs, where the local user's date is used, but
+		// the UTC timezone is specified. Gemfeed does this at the time of
+		// writing, but will not after #3 gets merged on its repo. Still,
+		// the older version will be used for a while.
+		curDay := toLocalDay(time.Now()).Add(26 * time.Hour)
+
+		for _, entry := range pe.Entries[start:end] { // From new to old
+			// Convert to local time, remove sub-day info
+			pub := toLocalDay(entry.Published)
+
+			if pub.Before(curDay) {
+				// This post is on a new day, add a day header
+				curDay = pub
+				rawPage += fmt.Sprintf("\n## %s\n\n", curDay.Format("Jan 02, 2006"))
+			}
+			if entry.Title == "" || entry.Title == "/" {
+				// Just put author/title
+				// Mainly used for when you're tracking the root domain of a site
+				rawPage += fmt.Sprintf("=>%s %s\n", entry.URL, entry.Prefix)
+			} else {
+				// Include title and dash
+				rawPage += fmt.Sprintf("=>%s %s - %s\n", entry.URL, entry.Prefix, entry.Title)
+			}
 		}
-		if entry.Title == "" || entry.Title == "/" {
-			// Just put author/title
-			// Mainly used for when you're tracking the root domain of a site
-			rawPage += fmt.Sprintf("=>%s %s\n", entry.URL, entry.Prefix)
-		} else {
-			// Include title and dash
-			rawPage += fmt.Sprintf("=>%s %s - %s\n", entry.URL, entry.Prefix, entry.Title)
+
+		if pageN == 0 && len(pe.Entries) > epp {
+			// First page, and there's more than can fit
+			rawPage += "\n\n=> about:subscriptions?2 Next Page\n"
+		} else if pageN > 0 {
+			// A later page
+			rawPage += fmt.Sprintf(
+				"\n\n=> about:subscriptions?%d Previous Page\n",
+				pageN, // pageN is zero-indexed but the query string is one-indexed
+			)
+			if end != len(pe.Entries)-1 {
+				// There's more
+				rawPage += fmt.Sprintf("=> about:subscriptions?%d Next Page\n", pageN+2)
+			}
 		}
 	}
 
@@ -86,7 +160,7 @@ func Subscriptions(t *tab) {
 		Raw:       rawPage,
 		Content:   content,
 		Links:     links,
-		URL:       "about:subscriptions",
+		URL:       u,
 		Width:     termW,
 		Mediatype: structs.TextGemini,
 	}
@@ -94,9 +168,11 @@ func Subscriptions(t *tab) {
 	setPage(t, &page)
 	t.applyBottomBar()
 
-	subscriptionPageUpdated = time.Now()
+	subscriptionPageUpdated[pageN] = time.Now()
 
 	logger.Log.Println("done rendering subscriptions page")
+
+	return u
 }
 
 // ManageSubscriptions displays the subscription managing page in
@@ -109,9 +185,13 @@ func ManageSubscriptions(t *tab, u string) {
 	}
 
 	rawPage := "# Manage Subscriptions\n\n" +
-		"Below is list of URLs, both feeds and pages. Navigate to the link to unsubscribe from that feed or page.\n\n"
+		"Below is list of URLs you are subscribed to, both feeds and pages. " +
+		"Navigate to the link to unsubscribe from that feed or page.\n\n"
 
-	for _, u2 := range subscriptions.AllURLS() {
+	urls := subscriptions.AllURLS()
+	sort.Strings(urls)
+
+	for _, u2 := range urls {
 		rawPage += fmt.Sprintf(
 			"=>%s %s\n",
 			"about:manage-subscriptions?"+gemini.QueryEscape(u2),

subscriptions/subscriptions.go

@@ -11,7 +11,6 @@ import (
 	"os"
 	"path"
 	"reflect"
-	"sort"
 	"strings"
 	"sync"
 	"time"
@@ -370,7 +369,7 @@ func updateAll() {
 	wg.Wait()
 }
 
-// AllURLs returns all the subscribed-to URLS, sorted alphabetically.
+// AllURLs returns all the subscribed-to URLS.
 func AllURLS() []string {
 	data.RLock()
 	defer data.RUnlock()
@@ -386,7 +385,6 @@ func AllURLS() []string {
 		i++
 	}
 
-	sort.Strings(urls)
 	return urls
 }
 
@@ -394,7 +392,7 @@ func AllURLS() []string {
 // The URL must be provided. It will do nothing if the URL is
 // not an actual subscription.
 //
-// It returns any errors that occured when saving to disk.
+// It returns any errors that occurred when saving to disk.
 func Remove(u string) error {
 	data.Lock()
 	// Just delete from both instead of using a loop to find it